1. Field of the Invention
The present invention relates to thermal image transfer. More particularly, the present invention relates to an apparatus and method of driving a thermal print head wherein an image is formed by consecutively printing at least two color images. The images are printed using a plurality of heaters within the thermal print head. The heaters are used in a heating order that is organized into phases to print the image sequentially.
2. Description of the Related Art
Generally, an image forming apparatus converts a document written by a user via an application program, or an image photographed with, for instance, a digital camera, into encoded data. The image forming apparatus outputs the encoded data onto printing media making it visible to the user.
A thermal transfer printer produces an image by applying heat onto an ink ribbon in contact with a printing medium by using a thermal print head. On application of heat, ink is transferred from the ink ribbon onto the printing medium. Alternatively, another type thermal transfer printer produces an image by applying heat to a printing medium that has an ink layer. A predetermined color is produced in response to heat provided by a thermal print head.
The thermal print head includes a plurality of heaters having a predetermined resistance R. The heaters supply heat to the printing medium in response to application of a predetermined voltage, VHD. By increasing the number of heaters, an improvement in printing quality can be achieved. Accordingly, the number of control signals required to control operation of the thermal print head increases as the number of heaters increases. Power P consumed by a single heater on application of voltage VHD can be calculated using Equation 1.
                    P        =                              VHD            2                    R                                    (        1        )            
Therefore, as the number of heaters increases, to obtain high quality images, the power consumed by the thermal print head also increases.